Toyota Repair: Toyota Sienna Signal Light, light functions, toyota sienna

Question
I have a 2003 Toyota Sienna Van. The Right hand signal light functions normally until you apply the brakes. A soon a you push on the brake pedal the signal light stops flashing but stays on. Whats wrong?

Answer
Check all of the bulbs especially if any bulbs were replaced recently, it's possible a wrong bulb is in one of the sockets ie: a single contact bulb in a dual contact socket or vice versa, check all the ground wire connections at the rear, they are white/black, make sure the grounds are tight, another problem could be the trailer towing wire harness if so equipped, there have been some problems with aftermarket installed towing packages.